> For the complete documentation index, see [llms.txt](https://docs.openbrim.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.openbrim.org/templates/precast-i-girder-bridge-workflow/bridge-geometry-pig/bridge-alignment-pig.md).

# Bridge Alignment \[PIG]

The ability to model and analyze multiple bridges within one project and assign different alignments to each bridge is a valuable feature of OpenBrIM, enabling engineers to efficiently design and optimize complex transportation infrastructure projects. To achieve this, OpenBrIM allows users to create and model multiple bridges within one project. Once the bridges are created, users can assign different alignments to each bridge in this section.

## General

It is recommended to define one bridge per project in OpenBrIM for optimal performance. However, if a project requires multiple bridges (such as two units sharing the same pier), the user can create additional bridges by creating a new row for each bridge and assigning the appropriate alignment to it.

**Alignment:** Assign alignment of the bridge (refer to the video at the end of [this](https://docs.openbrim.org/examples/steel-bridge-examples/example-steel-i-girder-bridge-ex1-sig/bridge-geometry-ex1-sig/roadway-alignment-ex1-sig) page to see how set operations can be performed using a spreadsheet).

**Is Pergola Structure \[No/Yes]:** Set to Yes when the bridge represents a pergola-type structure (girders supported by transverse beams/columns without a typical continuous span layout). Affects span detection and framing logic. Default is No.

## Bridge Info

The following information is not essential for analysis, design, and modeling purposes, but can be used to store additional details about a bridge project.The definitions made in this section can be used to generate the Soil Boring Log Report. The parameters associated with Bridge Info are as follows:

**Structure No:**

**Station:**

**Route:**

**Description:**

**Section:**

**Location:**

**County:**

## Referencing Objects

**Span Locations:** List of span-location objects that reference this bridge alignment. (Read-only)

**Roadways:** List of Roadway objects that reference this bridge alignment. (Read-only)


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